Fernco P3000-33 Proflex Shielded Specialty Couplings, 3" x 3", Chrome Provides a connection between similar and dissimilar pipe materials and sizes without the use of bushings The internal pipe stop insures proper installation and reduces noise and vibration The outer shear ring and clamp assemblies conform to astm a a167-91 Specialty coupling Shielded Coupling Connects cast iron to plastic, steel or extra-heavy cast iron, drain waste and vent systems 3 inch cast iron to 3 inch plastic, steel, or extra-heavy cast iron